The aim of this study is to investigate the effect of computer-aided Perspective Drawings on eighth grade primary school students' achievement in Spatial Orientation and Perspective Drawing. The study made use of pre-test post-test control group experimental design. The study was conducted with thirty 8th grade students attending a primary school in Turkey in 2009-2010 school year. The lessons of the control group students (n=15) were performed in an activity based way by using the board and paper for two weeks (8 class hours). In the lessons of the experimental group students (n=15), on the other hand, Perspective Drawing applications were carried out using computer-aided teaching method for two and a half weeks (10 class hours). A Spatial Orientation test was used to monitor the students' achievement in Spatial Orientation and a Perspective Drawing test was used to examine their achievement in Perspective Drawing. According to the results from the analyses, both Spatial Orientation and Perspective Drawing achievement levels of the subjects increased significantly in both the experimental group and the control group. However, it was determined that there was a statistically significant difference between the Spatial Orientation test rank-score means and the Perspective Drawing test rank-score means of the experimental group students and the control group students. It was concluded in light of these findings that computer-aided Perspective Drawings increased student achievement in Spatial Orientation and perspectivity.